Why do you think it was a Rainbow?
I had a dream last night that Noah was gay. God saw how horrible the world was and decided the whole of creation needed to be reset, so God got Noah and his partner, who both looked really buff, and explained the plan and that they would have to gather all the animals on board the ark.
Noah, perplexed by this plan, wondered aloud to God about what would happen after he and his partner died off and there were no more humans left. God led them down into the lower levels of the ark where there were these humanoid robots in various states of construction.
"These will replace humans as caretakers of my creatures," said God. "They can't do any worse than humans have."
And that's where the dream ended.